The biological effects of 60 hertz electric fields will be studied to provide a basis upon which to assess the risk of exposure to such fields in the environment. Specifically determined will be; (a) the effect on mice of chronic exposure to 3.5 kv/m for three generations, (b) the effect on various physiological parameters of rats of 1-30 days exposure to 3.5 kv/m, and (c) the effect of 0.5-10.0 kv/m for 1-5 days on gross motor activity of mice. Other related studies will also be performed.